A helicopter is hovering 490m above ground. A package is dropped from the heli, and 2 seconds later a 2nd package is dropped from same position.

Find expressions for differences in height, distinguishing the cases 0-2, 2-10, 10-12 and >12 seconds.

Sketch a graph to show the differences in height and find its greatest height, and find its greatest value

answer given: 4.9 t^2, 19.6(t-1)m, ( 490-4.9(t-2)^2)m, 0; 176.4m

thank you so very much